Abstract
Calorimetric data on heats of fusion of rocks have been very limited. In our investigation, high-temperature drop calorimetry was performed to measure heats of fusion of mantle rocks in the system CaO-MgO-Al2O3-SiO2. Heats of fusion of natural mantle rocks under high pressure were estimated by correcting effects of FeO and Na2O components, pressure and temperature on melting enthalpies to the observed heats of fusion. It is suggested that mixing enthalpy of silicate melt in the system CaO-MgO-Al2O3-SiO2 is nearly zero by comparing the heats of fusion determined calorimetrically with those calculated by summing melting enthalpies of CaAl2Si2O8, CaMgSi2O6, MgSiO3 and Mg2SiO4.
